Follow these steps first:
Create an SendinBlue account here
Create three email lists in SendinBlue, e.g. Customers, Subscribers and Abandoned Cart users (or use your existing SendinBlue lists)
Start the app install flow here, click GET to start
Export current users? Select YES or NO
Select your Abandoned Cart time trigger (e.g. 15 minutes or 1 hour)
Click 'Next' when you are on a new Shopify theme (after Oct. 2016)
Connect your SendinBlue account
Select the lists in the app configuration
Finish the app installation flow
Which fields are synced into SendinBlue?
The following fields are synced to SendinBlue:
Adding a newsletter signup
Although you can't email customers through your Shopify admin, you can use the Shopify SendinBlue app to send promotional emails. Email marketing apps usually work by syncing your Shopify customer data with a third-party email marketing service like SendinBlue.
How to add a newsletter signup section to your online store
All free Shopify themes have a newsletter signup section that you can add to your home page.
To add a newsletter signup section:
From your Shopify admin, go to Online Store > Themes.
Find the theme that you want to edit and click Customize.
Click Add section.
In the Promotional area, click Newsletter > Add.
To display header text in your newsletter section, check Show header.
In the Header field, enter the header text. For example, you could type "Subscribe to our newsletter".
How do I use Abandoned Cart features?
The app synchronizes all abandoned cart users into a list of choice into SendinBlue. Use this list to send out your abandoned cart email.
Hope we'll save you precious time :)